Combined telephone-exchange and alarm system.



J. M. LATIMER. COMBINED TELEPHONE EXCHANGE AND ALARM SYSTEM.

APPLICATION FILED APR. 21, 1900. 904,441

Patented Nov. 17, 1908.

2 SHEBTSSHEE'I' 1.

Witnesses: In n L if John Morris a rmer, W :5 Z

J. M. LATIMER. COMBINED TELEPHONE EXCHANGE AND ALARM SYSTEM.

APPLICATION FILED APR.21, 1900.

Patented Nov. 17, 1908.

2 SHEETS-SHEET 2 9a. Me

Invehtor VV'ltnessesf W Juhn Morris L alimer, fa, Affor e iED STATES rATENT OFFICE.

JOHN MORRIS LATIMER,, QF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO CONSOLIDATED FIRE ALARM COMPANYJA CORPORATION OF NEW YORK.

COMBINED TELEPHONE-EXCHANGE AND ALARM SYSTEM.

To all whom it may concern:

Belt known that I, Jenn Monms LATI- Mnn, a citizen of the United States of America, and a resident of the citv of Philadel-- In this, as well as. in the invention setv forth in the above mentioned application, the object is to utilize existing telephone lines for the transmission of fire-alarms, burglar alarms, or other signals, from various points within a territory covered by a telephone-exchange system to a fire, police or other alarill-receiving headquarters, by means of suitable local transmitting apparatus and repeating apparatus connected to the telephone-lines, but so constructed that they will not interfere with the telephonesignaling or talking currents, or the sets of local telephone-apparatus at the various; points. telephone-subscribers circuits, which come together in a telpl'ione-exchange, are used for two distinct and independent classes of service. These are,-first, an exchange-service, in which local teieplnme-subscribcrs nail to a telephone-exchange and obtain telephone-connections with one another; and, second, a service in which suitably arranged and connected sets of apparatus at various points are provided. with which signals can be. transmitted over the leads of the telephone-subscribers' circuits, and these signals are received at a point which is separate and distinct from the tclephone-exchange. This second service is by way of distinction termed an alarm-service.

The sets oi apparatus for the alarmservice at the various points from which signals can be sent. ar ic l s is of local alarmiransmitting apparatu a 1 die-apparatus at the point to which the signals are sent will be termed the alarm-rccciving apparatus. These terms, however. are not intended to limit the claims to systems in which the signals are distinctly alarmln other words, the'leads of tho.

Specification of Letters Patent. Application filed April 21, 1900. Serial No. 13,762.

Patented Nov. 17, 1908.

signals, since the system is equally applicable to the transmission of signals for any purpose. I i

In the system as herein disclosed, neutral relays are placed in the leads of the tele- 'ihone circuits at the exchange to repeat the signals from the telephone-circuits'to the circuits extending to the alarmaeceiving headquarters. The telephone-lines are also utilized for transmitting answering signals to the local points from which the alarm-signals are transmitted, and to establish direct telephone connection between the points from which the alarm-signals are transniitted and the alarm-receiving headquarters.

The construction is such that these objects are attained without interfering with the ordinary telephone-exchange service over the lines.

The telephone-circuits radiate from a telephone-exchange to various sets of telephonesubscribers apparatus, and these circuits are primarily constructed for the purpose of connecting the telephone-subscribers with the exchange. The sets of alarm-transmitting apparatus are connected to the lines of the telephone-circuits which are most conveniently reached, and the system such as not to interrupt the telephone-excl:augc service, or be interiaipted by the telephoneexchange service. The construction is also such that the telephone-s1ibscriber's service is not interrupted at any time or dir-zturbed, except at. the actual instant of sending signals. The signals from the sets of local alarm-transmitting apparatus are received l alarm-repeating relays at the telephonecxchange. These relays are so constructed that they will respond to signals from the sets of local alarm-ai'iparatus, but will not respond to. the tclephonesiihscvihers signaling and talking currents.

The alarm-signal currents may or may not a that the telephone signal-receiving devices at the snitchboard. but it' they do, their special character will be easily recognized by the exchange-opcrators, and not be mistaken for tclephone-subscribers calls. The signals areautomatically transmitted by the alarmrepeating relays in the tclcphone-eircnits to the alaran-receiving hcmlquarters, and their transmission is consequently independent of any attention from the exchangeoperators, and. therefore; not subject to' the danger of oversight or delay on their part,

as would be the case it they were required to repeat the signals. The construction also is such that it is innnaterial 'hether or not the telephone-circuit is in use for conversation and connected to another telephonecircuit at the exchange, when called upon for the transmission of alarm-signals. It is important to be independent of this condition, because, when the telephone circuit is connected to another exchange by means of a trunk connection, the telephone-snbsciahefs clearing-out signal would, accordin to usual telephone practice, be cut out at the local exchange. and only be received in the exchange at the long-distance point, in the event that the distant subscriber is the calling subscriber, and, therefore, if an alarn'i-signal depended for indication upon the local exchange, there would be no means, under these conditions, of indicating it at the local exchange, and itwould go to the distant exchange instead, which might be in another city.

In the accompanying two sheets of drawings, which form a part of this specification, Figure l is a diagram showing an alarm-system, applied to a common-battery exchange in which the alarm-transmitting sets and the alarm headquarters are in communication through a duplex telephonesystem. Fig. 2 is a diagram showing an outdoor police telegraph and telephonesystem, an out-door public fire-alarm telegraph and telephonesystem, andan indoor. automatic or manual private alarm-service, all applied to a common-battery exchange, as in Fig. 1.

The system as shown in Fig. 1 will first be described :The telephone-subscribers sets 1, of. which but one is shown, are connected to a common-battery telephone-exchange by the battery-leads 2 and grounded leads 3, which form the telephone-subscribers circuits and connect the subscribers sets with the open-terminal spring-jacks 4 and the grounded common-battery 5. The battery leads are connected through line-signal relays 6 to the live terminal of the commonbattery, and the grounded leads are connected to the grounded terminal of the commom-battery. The line-signal relays close circuits through line-signal lamps 7 5 In front of the spring-jacks for each circuit are test rings 8, which are connected through an exchange cut-0E relay 9 to the grounded ter.- minal of the common-battery. The insertion of the u'sual exchange cord-circuit plug in the jack of a telephon'e-subscribefs circuit, connects the test-ring with the live terminal of the battery, and with the cut-off relay shifts the connections of the grounded lead of the telephone-subscribers circuit to ground through a repeating-coil in the cordcircuit, and shifts the connections of the battery-lead of the telephone-subscribers circuit in the battery through another repeating-coil in the cord-circuit. In the cord circuit are placed signal-lamps, which light on the cessation of battery current. Such a cord circuit is illustrated in United States Letters .Patent to H. M. Crane, No. 620,745,

are made have, in both leads at the exchange,

alarm-repeating relays 12, which are neutral relays, with the coils balanced in the two leads. All currents, which are used in signaling and telephoning between telephonesubscribers and the telephone -exchange, course through both leads and both coils equally, but oppositely around the relaycore, thereby neutralizing each other, and, hence, do not affect the relay. But when a contact is made by the a]arm-transmitting apparatus between the battery-lead of the telephone-circuit and the ground, the common-battery current will flow tl'irough one coil only of the relay and it will attract its arn'iature. Each relay controlscontacts 13, which are in multiple in an alarm-transmit.- ting circuit 14. The closure of the contact at any relay, therefore, closes the alarm-.

transmitting circuit. With the system connected as illustrated, the sending. of an alarm-signal would cause a flashing of the line signal-lamp, which would be recognized by the exchange-operator as an alarm-signal, and not as a subscribers call, and no attention would be paid to it by the exchange- .operator, whose business is to answer subscribers calls and connect telephone-subscribers. If, while such an alarm vere coming in, the telephone-subscriber of the line should take off his telephone-receiver, the flashing signal-lamp would change to a continuous light, thereby indicating a subseribers call,'and thealarm-signals would cease to flash on the lamp, although they would continue to operate the neutral relay,-

and be repeated thereby to the alarm-headquarters.

in. In serles wlth each relay-contact 1s a 001m,

of an automatic cut-out switch magnet 15 and a slow-acting cut-out switch 16 which is controlled by the cut-out switch magnet and opened when the. magnet is fully energized.

The core of each of these magnets, especially at the pole-pieces, is surrounded with copper sleeves so that the magnet will magnetize slowly and Willnot attract its armature and open the alarm-transmitting circuit until after a short interval. The cut-out switch magnet is also made to respond slowly to current by providing it with two armatures so adjusted that the one controlling the contact will not be attracted to the core until the other hasbeeen attracted to the core, and has thereby strengthened the magnetic circuit. Between the closure of the alarm-transmitting circuit at the relay and the opening of this circuit by the cut-out switch there is sufficient time to send an impulse such as is requisite in sending a signal. Because of the construction above indicated, this cutout switch operates whenever current comes into its coil and remains for a length of time, consequently in event ofany current coming onto a line, which would operate its alarm-repeating relay, and remaining on, thiscut-outswitch magnet will operate and open that branchof the alarm-transmitting 'ci-rcuit which is through'the relay-contact made by the alarn'i-re 'ieating relay, so that signals. received on other alarm-repeating relays can be repeated on thls alarm-transmitting circuit. The purpose of this cut-out grounding of, 'or the presence of a foreign switch is,therefore, to prevent the complete disabling of the entire alarm-system through the individual disabling by the continuous current in, any one of thetelephone-circuits which is utilized for transmitting alarm-signals. .Thecut-out'magnet on operating and opening the alarm-transmitting circuit, ef-

fects the closure, of a contact 17 of a circuit through its coils and the contact of the neutral relay. As long as the grounding of the line or foreign current continues on the line, the contact 13 remains closed, and the. cutout switch-magnet ISremains energized, and

the contact 17 remains closed, since there will be a-circult from the common battery through the cut-out switch-magnet, through i the contact 13', and through the contact 17 to the other side of the common battery.

It, therefore, remains cnei n as long as the relay rcn iains energized, and prevents any pern'ianent closure of the alarm-transn'iitting circuit at the relay. Upon the cessation of the current which rendered the individual alarm-relay inoperative, the cut-out magnet will release its armature and the alarmtransmitting circuit will be restored to coin trol by the neutral rcla in the circuit which was disabled.

' The alarmJinnsmitthw circuit 1i is whollywithin the exchange and is preferably a normally open circuit. it is supplied from the commo'n-baltery and contains a rclay 18 which controls a contact in a second transmitting circuit 19 extending to the reiay 20 at the alarm cciving hcadquarters. in order to save wins, the telephone leads 21 between the headquarters and the exchange are used in parallel for the transmission of these signals by a duplex arrangement, which is non-interfering with the telephone circuit. Branches from both leads pedance coils 2'2 and joined to the lead of the circuit 19'. Branches from both leads at the exchange are led through impedance coils and joined to the leads of the circuit 19. The circuit is from the commonbattery through the contact of the relay 18 to the pointof juncture of the branches from the telephone-leads at the exchange,

the impedance coils in the exchange branches, the telephone leads, the branches from the telephone-lea ls and the impedance cdils to the point of juncture at the headquarters, thence through the relay 20 and telegraplrkey 23 to ground, and back to the common battery, thus completing the circuit. The relayQO, on operating, closes a local circuit" through a local battery 24, and an alarm-receiving apparatus consisting of a register and bell 26. The transmitter and primary coil of the telephone-set 2? at the headquarters is also in this circuit.

The leads from the receiver and secondary coil of the telephone-set are carried to repeating-coils 28 on the cores of the neut 'al relays in the tclepholie-subscribers circuits at the exchange. These coils are all connected, so that current, which may be induced in any one of the coils, will also flow in the others. As shown in the drawings, they are connected by placing them in series in the circuit of the telephone at the headquarters. As the neutral relays are balanced with respect to the subscribers" circuits, currents in the repeatingcoils will not repeat to these circuits. They will, however, each repeat to circuits in parallel over each of the telepholie-subscribers leads which join through condensers 29 in circuits through the receiver and secondary coils ofv each oi the local alarm-tclepl'mne sets 30 which are placed in conjunction with the local alarmtransmiiting sets. The connections with 5 each pair of telcpl1o!ie-subscribers leads is through two impedance-coils .22. These coils are non-iinluciive to currents passing through them in parallel. but alternating currents will not pass through them in series. 'lhesecoils arc. wound onan iron core, which forms a closed ring, and the connections lo the windings are such that if the course of the current be traced through one coil, thence through the point of connection 01 the two coils with the local alarm telephone-set. and thence back through the other coil, the circuit through both coils will be around the core in the sane direction as though the two coils formed one continuous spiral. .'\u alternating current attempting at the headquarters are led through im-' thence in parallel over these branches and rents. On the other hand, an alternating current to or from the local alarm telephoneset will divide equally between the two coils,

and, passing around the core simultaneously in contrary direction, will be neutral in 1nagnetizingefl ect on the core, and there can be no rise of magnetization in the core to oppose the passage of such currents. The circuits in parallel are carefully balanced,

so that they will neutralize each other withrespect to the telephone-subscribers apparatus. The condensers in the branches of the telephonesubscribers circuit prevent the closure of this circuit through them to continuous currents, and hence do not afford a closed circuit to the common-battery. The

repeating-coils 28 are Wound with two parallel wires, and after ,Wllldll'lg one wire 1s connected in series with the other to reduce the impedance. Each repeating coil may be of ordinary construction, but I prefer, and show, a bi-filated winding. Twowires are wound together, and the wires of two windings, when completed, are connected in series. There is then a condenser effect between the two coils, which reduces the self-induction of the coils.

The sets of local alarm-telephone apparatus are constantly connected through the neutral relays and repeating-coils with the telephone-set at the alarm-headquarters, and with each other, it being necessary only to remove the receivers from the hooks to place them in communication. As the local-battery circuit through the telephone-transmitter at the alarm-headquarters is closed when the bell is sounded, it follows that the sounding of the bell. at the headquarters can be heard in any telephone of the sets of local alarm-apparatus, and a person, when sending 'an alarm, can, by first listening in the telephone, ascertain whether or not he will interfere with a user of the system'between any other locaL alarm-apparatus. and the headquarters. "liy continuing to .listen While signaling, he can also ascertain whether or not his signals are properly sounded at the headquarters. The alarm-transmitting ap paratus and the alarm-receiving apparatus in each set of local alarm-apparatus are in different circuits, although they may use the same leads, and are independently operating, except for their connection through the relays and circuits at the telephone-exchange and at the headquarters- The opermon battery 5 can then flow through the subscribers line-signal relay .6, upper con--- tact of the cut-out switch 9, telephone battery lead-2, coil of neutral relay 12, primary of subscribers induction coil, hook, mitter, grounded lead 3, coil oi neutral relay. 12, in contrary direction to other coil.

of this relay and thereby not affecting it, lower contact of cut-out switch 9 to ground side of the battery. This circuit ,encr izes the line signal relay 6, and this relay c oses a circuit from battery 5 through the lamp 7 which notifies the exchange operator that the subscriber desires telephone connection. Insertion of a plug by the exchange opertransator at the headquarters can acknowledge and answer the signals, either by telephone ator energizes the cut-off relay 9 thereby disconnecting the leads 2 and 3 from the bat tery 5 through the line signal relay, but the" leads are at the same moment again connect,- ed to the battery through repeating coils in the cord circuit'in the usual ,Way.

The variations thebattery current intalking: are of course insufilcient to be manifested at any of the relays. They are in contrary directions through the coils of. the neutral relay 12, and they do not affect this coil, the talking current will not pass through the branch across .the leads 2 and 8 through the impedance coils 22, for since their course is the same in each coil, their inductions are opposed. Battery current will not pass this branch because of the condensers 29.

When an alarm is transmitted by closure either at the signaling wheel'10 or key 11, a circuit is established from the common battery through the line signal relay 6', one coil of neutral. relay 12 thereby operating the relay, lead 2, signaling wheel'10 or key 1 1 to ground of the local alarm transmittmg apparatus, thence through the ground at the exchange to the other side of the battery.

If at the time this signal is transmitted, the

line is in use by, a subscriber, the circuit will be from the common battery through one of is in telephone lead 2, ground at the local the repeating coils in the cord circuit, cord which is connected to the lead 2 will consequently exceed the current which is returning from the subscril'iens set over lead 3 and through the other coil of tlie'neutral relay. The coils will therefore be out of balance and the relay will be operated as before.

Operation of the neutral relay closes a circuit located entirely within the exchange. This circuit is from the common battery 5, through the automatic cut-out magnet '15, contact of the neutral relay, a contact 16 which is opened when the' automatic cut-out magnet has fully operated its armatures and relay coil 18 to the ground side of the battery. The operation of the relay 18 opens a circuit to the alarm receiving headquarters.

This circuit is from the common battery over the lead 19, a contact on the back of the armature of the relay 18, through impedance coils in parallel over the telephone leads 21 between the alarm headquarters and the telephone exchange. through impeda ce coils to the point of uncture at. the headquarphone set 30 and the telephone set 27 at the headquarters is over a circuit over the condensers 2!) in parallel the impeiance coils 22 in parallel thetelephone subscriber's leads 2 and in parallel, the coils of the neutral relay 12 in the same direction, from lead 2 through linesignal relay 6 and common battery to ground, andfrom lead 3 to the common batterv ground at the exchan e and returnthrongh the ground at the local alarm trinismitting station. Then talking currents are repeated by induction upon the neutral relay coils,12- to repeating coils 28 in a circuit consisting of two leads between the exchange, where the repeating coils are located and the telephone receiver andinduction coil at the a la rmreceiving headq uarters.

The several classes of circuits in use in the. transmissitm of an alarm are open circuits with the exception'o't' the circuit between the l l l exchange and the alarm receiving headquarters. For su'ch important service as the transmission of alarms, it is desirable thatcircuits which are between different parts of a cit and therefore cannot be as carefully protected .as circuits wholly within instruments or buildings should be normally closed circuits in order that they-may be constantly under battery test, as then any interruption would immediately become known and could be more promptly repaired. But in utilizing telephone circuits this is not necessary since their frequent use for telephone purposes affords sufficient warning of any'interruption. As the circuit between the exchange and the alarm receiving headquarters is used for the transmission of all alarm signals it is of special importance that immediate warn ing should be given of any accident and this circuit is therefore preferably arranged as a normally closed circuit.

The system as shown in Fig. 2 will now be described. This shows a common-battery te phone-exchange, as in Fig. l, with five complete telepholie-subscribers sets and circuits connecting them with the exchange. The telephone-circuits are. utilized for three classes of alarm-service, and the alarm-signals in each class are received in separate alaI'm-transmitting circuits at the exchange. These three classes of service are as to]- lo\\'s:(a),.' .n out-door public or municipal tire-alarm service for useby policemen, fire men and others, conu'n'ising sets of local lire alarm apparatus each consisting of ant matic. or manually operated signalingwheels 1t? a telegraph-key l1 and a telephone-set 30 for sending fire-alarm and special signaling to and atfording direct tele phone communication through relays 12 and 18 telegraph circuits lit and 19 and telephone circuits 21 with the headquarters apparatus, comprising the relay register 25, bell 26 and telephone set 27; (b) an out-door public or municipal police service comprising sets of local police signal apparatus, each consisting of a manually-operated signaling wheel 10, a telegraph-key 11 and a telephone-set 30" for sending signals to and affording direct telephonic communication through relays 12 and 1S telegraph circuits l4" and 19 and telephone circuit 21 with the police headquarters apparatus, comprising the relay 20*, reg ster 25", bell 26 and telephone-set 27"; (c) an in-door automatic or manual private alarm service for sending distinctive signals by means of a local alarm set with a signaling-wheel 10 through relays 12 and 18,and through circuits 14 and 19 to a private fire, police or other alarmareceiving headquarters, comprising the relay 20, register 25 and bell 26".

The apparatus and circuits for the first two of the three foregoing classes of service are substantially identical in their arrangeparatus differ from the sets of local police signaling-apparatus in that the former is provided with mechanism for rotating the signaling-wheel a number of times, and

thereby repeating the signal, while themechanism of the police signaling-apparatus imparts but onerevolution to the signalingwheel at each operation. I

In the diagram, the sets of local out-door public fire-alarm apparatus are connected to the first and third telephone-subscribers circuits, the sets of local out-door police signaling-apparatus are connected to the second and fourth telephone-subscribers circuits, and the signaling wheel for the iii-door automatic or manual alarm apparatus is connected through the fifth telephone-circuit Additional sets of local police, fire, and other alarm-apparatus are connected to additional telephone-circuits as may be required. The sets'of local out-door fire-alarm apparatus and the sets of local police-signaling apparatus may be entirely distinct, and the sets located wherever they will be most convenient. But whereverit is desirable to have them near each other, they may be conveniently housed in the same box or casing, as shown in the sets of fire alarm apparatus connected to the, first telephone circuit and the set of police-signaling apparatus connected to the second telephone-circuit. When this is done, one telephone-set 30 will serve for both, a switch 31 being provided to shift the telephone connection to either class of service.

But one of the local stations of the in-door automatic service isindicated in the diagram. Two signaling wheels 10 and 109 are shown, and are operated by the same mechanism, which may be such as is shown in connection with the municipal fire-alarm service. One of the wheels connects one of the leads of the telephone circuit to round, and the other connects the other lea to ground. I t is only necessary that the lead which is connected to the same common-battery at the exchange should be grounded, and the object of the other NVllCGl is to guard against the local-alarm set being rendered inoperative by a transposition of the telephonewires at any point between the point of connection of the local set and the exchange battery. The wheels are preferably arranged so that both leads will be connected to ground at the same moment.

The signals from the iii-door automatic service are received at the exchange in the circuit 14 and repeated by a relay 18 to the private alarm-receiving headqiuirters.

A register 32 is also connected with this relay, so that ie signals will be recorded at the exchange. A second relay 33 is also placed in the circuit 14", and controls a contact in the municipal fire-alarm circuit. But

this contact is normally short-circuited by an automatic switch 34, so that the first automatic alarm-signal will not be repeated 'onto the municipal alarm-circuit, for such first signals are usually local trouble or test signals, and their indication at the fireheadquarters would 'be objectionable'to the fire departments. The automatic switch is in the form of a contact-wheel, and is con nected to a gear-train, which is released for any of the circuits of this-class will be cut,

out from the municipal fire-headquarters.

Vhat I claim and desire to secure by Letterslatent of the United States is:

1. The combination of a telephone-apparatus, a telephone-exchange, a telephone-circuit connecting the tclephone-apparatus with the telephone-exchange and grounded at the exchange, a local alarm-transmitting apparatus for effecting grounded connections with one of the leads of the telephone-cir-' cuit, a battery in the circuit which is estab- This mechanism,- whenever started,

lished by the local-alarm-transmittingapparatus through the groundat the exchange. a neutral relay in the leads of the telephonecircuit, the relay being at the, exchange and responsive to currents controlled by the local alarill-transmitting apparatus and not to the telephone-signaling and talking currents. and an alarm-receiving apparatus which ,is independent of the telephone-circuit and is controlled by the relay, substantially as de scribed.

2. The combination of a telephone-apparatus, a telcphone exehange, a telephone-circuit connecting the telephonc-apparatus with the telephone-exehange and having one of the leads grounded at the exchange. a local alaIan-transmitting apparatus for establishing grounded connections with the telephone-circuit. a battery in the circuit which is established by the local alarm-transmit- I ting apparatus through the ground at the exchange, a neutral relay inthe leads of the telephone-circuit, the relay being at the ex change and responsive to currents controlled by the local alarm-transmitting apparatus and not to the telephoiie-signaling and talking currents, and an alarm-receiving apparat-us which is independent of the telephonecircuit and is controlled by the relay, substantially as described.

3. The combination of a telepl1oncapparatus, a telephone-exchange,a grounded conimon-battery therefor, a telephone-circuit connecting the telephone-apparatus with the telephone-exchange and having one of the leads connected with the common-battery and the other lead grounded at the exchange, a local alarm-transniitting apparatus for establishing grounded connections with the lead which is connected to the common-battery, a neutral relay in the leads of the telephone-circuit, the relay being at the ex;- change and responsive to currents controlled by the local alarm-transmitting apparatus and not to the telephone-signaling and talking currents, and an alarm-receiving apparatus which is independent of the telephonecircuit and is controlled by the relay, substantially as described.

i. The combination of sets of telephoneapparatus, a telephone-exchange, telephonecircuits connecting the sets of telephone-21p paratus with the telephone-exchange and grounded at the exchange, a local alarmtransmitting apparatus for establishing grounded connections with one of the leads (it each telephone-circuit, a battery for supplying the circuits which are established through the ground at the exchange, a new tra'l relay in each pair of leads of each telephone-circuit, the relays being at the exchange and responsive to currents controlled bylhc sets of lo ral ilarin-transinitting apparatus and not to the telephone-signaling and talking currents. an alanil-transmitting circuit at the exchange which is controlled by any at the relays, and an alarm-receiving apparatus which is operated from the alarmtransmitting circuits, substantially as described. i

, The combination of sets of telephoneapparatus, a telephoneexchange, telephonecircuits connecting the sets of telephone-apparatus with the telephone-exchange and having one of the leads of each telephonecircuit grounded at the exchange, a local alarni-transinitting apparatus for establishing grounded connections with each telephone-circuit, a battery forsupplying the circuits which are established by the. sets of local alarm-transmitting apparatus through the ground at the exchange, a neutral relay in each pair of leads of each telephone-circuit the relays being at the exchange and responsive to currents controlled by the sets of local alarm-transmitting apparatus and not to the telephone-signaling and talking currents, analarm-transmitting circuit at the exchange which is controlled by any of the relays, and an alarm-receiving apparatus which is operated from the alarm-transmit ting circuit, substantially as described.

6. The combination of sets of: telephone apparatus, a telephone exchange, a grounded common-battery therefor. telephone-circuits connecting the of telephone-appa'atus -with the telephone'exchange. one of the leads of each circuit being connected to the com inon-battcry and the other being grounded at the exchange. a local-alarm transmitting apparatus for establishing grounded connections with the lead of each telephone-circuit which is connected to the common-battery,

a neutral relay in each pair of leads of each telephone-circuit, the relays being at the ex change and responsive to currents controlled by the sets of local alarill-transmitting apparatus and not to the telephone-signaling and talking currents. an alarni-transinitting circuit at the exchange. which is controlled by any of the relays, and an alarm-receiving apparatus which is operated from the alarmtransinitting circuit, substantially as described. I

7. The combination of sets of telephoneapparatus. a telephone exchange, telephonecircuits connecting the sets of telephone-apparatus with the telephonc-exchange, a local alar1n tra1isinitting apparatus connected to one of the leads of each telephone circuit, a relay in each telephone circuit, the relays being at the exchange and responsive to currents controlled by the sets of local alarmtransnntting apparatus and not to the telephone-signaling and talking currents,- an alarm-transinitting circuit at the exchange which is controlled by any of the relavs, a slow-acting cut-out switch magnet operating in conjunction with each relay to cut ofi' the control of the alarm-transmitting circuit by the relay, and an alarm-receiving apparatus which is operated from the alarm-transmitting circuit, substantially as described.

The combination of sets of telephone subscriber's apparatus, a telephone-exchauge, telephone circuits connecting the sets of tele' phone-subscribers apparatus with theytele phone-exchange, a local alarm-transmitting apparatus for sending alarms by establishing grounded connect-ions with one of the leads in each telephone-subscribers circuit, abattery for supplying the circuits which are established through the" ground at the exchange, a neutral relay in each pair of leads of each telephone-circuit, the relays being at the exchange and responsive to currents controlled by the sets' of local alarm-transmitting apparatus and not 'to' the telephone-sub: scribers signaling and talkingcurrents, alarm-transmitting circuit at the exchange which is controlled by any of the relays, a local alarm-receiving apparatus in conjunction with each local alarm-transmitting a pparatus, and means for operating each local alarm receiving apparatus from any of the sets of local alarm-transmitting apparatus,

substantially as described.-

9. The combination of sets oiiteiephonesubscribers apparatus, a telephone-exchange, telephonecircuits connecting the setsof telephonesubscribers apparatus with the telephcne exchange, a local alarm-transmitting apparatus for sending alarms by establishing I grounded connections with one of the leads in each telephone-circuit, a battery for supplying the circuits which are established through the ground at the exchange, a neutral relay in each pair of leads of each telephone-circuit, the relays being at the ex change and responsive to currents controlled by the sets of local alarm-transmitting apparatus, and not to the telephone-subscribers signaling and talking currents, an alarmtransmitting circuit at the exchange which is controlled by any of the relays, a local alarm-receiving apparatus in conjunction with each local alarm-transmitting appara tus, the sets of local alarm-receiving apparatus being connected to the leads of the telephonesubscribers circuits in circuits which are independent of the circuits through the sets of local alarm-transmitting apparatus, and means for operating each 10- cal-alarm-receiving apparatus from any of the sets of local-alarm-transmitting apparatus, substantially as described.

19. The combination of a telephone-apparatus, a telephone exchange, a grounded common battery therefor, a telephone circuit connecting the telephone-apparatus with the telephone-exchange and having oneof the leads connected to the common-battery and the other lead grounded at the exchange, a local alarm-transmitting apparatus for establishing grounded connections to both leads'of the telephone-circuit, a neutral relay in the leads of the telephone-circuit,

and responsive ,to currents controlled by the local alarm-transmitting apparatus and not to the telephone-signaling and talking cur- "rents, and an alarm-receiving apparatus which is independent of the telephone-circult and is controlled by the relay, substantially as described.

11. A combined telephone and alarm sys-.

tem comprising the combination of a telephone instrument, an alarm instrument, a telephone exchange, a common circuit con.- necting the telephone and alarm instruments with the exchange, av source of operating current therclor at the exchange, an independent electrical connection from the alarm instrument to the source of current at said exchange, an alarm receiving apparatus with connections, and automatic means connected. with said common circuit at said exchange pcri'nittii'ig signal and talking currents to pass between said exchange and said telephone instrun'ient without nfecting said 2 arm receiving apparatus but causing signals from said alarm instrument to be transmitted to said alarm receiving apparatus.

12. A combined telephone and alarm system comprising, a telephone instrument, an alarm signaling instrument, a telephone exchange. a common circuit having two leads connecting the telephone and alarm instruments with the exchange, a common battery for said circuit and at said exchange, an independent circuit connecting said alarm instrument and said exchange and connections for establishing a circuit between said independent circuit and both leads of said common circuit between said telephone instrument and said exchange.

.13. A combined telephone alarm system comprising the combination of the telephone exchange, line wires leading therefrom, an alarm receiving instrument with leads connected to said exchange, a telephone instrument connected to said line wires, alann signaling apparatus connected to said line, a telephone instrument connected with said alarm signal instrument, a'telephone instrument connected to said alarm receiving instrument leads and means for preventing the ordinary telephone and signaling currents from being transmitted to said alarm receiving instrument but permitting the alarm signals to be transmitted.

14. A combined telephone and alarm system comprising a telephone exchange, line wires leading therefrom, a telephone instrument connected to said wires for talking through said exchange, iilarm signaling apparatus having a grounded connection with said exchange and connected to send an alarm through a circuit including one of said line wires and said grounded connection, alarm receiving apparatus connected to said exchange, a coil Winding connected in each of said line wires, and means 00-,

acting therewith for automatically transmlttmg alarm signals between said signaling and receiving, apparatus, but permitting ordinary signaling and talking currents to pass between said exchange andsaid telephone instriiiment. V

15. A combined telephone and alarm system comprising the combination of a tele phone exchange, a telephone instrument with a complete circuit to said exchange, alarm signaling apparatus connected to said circuit, alarm receiving apparatus, a coil winding in each branch of said-circuit, so arranged as to permit the ordinary signaling and talking currents to be transmitted through said circuit, and means for causing alarms from said signaling apparatus to be automatically transmitted to saidreceiving apparatus.

16. A combined telephone and alarm system including a telephone zxchange, a telephone instriiment, a complete circuit between said instrument and said exchange for transmitting signaling and talking currents, alarm signaling apparatus connected to said circuit, alarm receiving apparatus connected to said exchange, a telephone instrument connected with said alarm signaling apparatus, atelephone instrument connected with said alarm receiving apparatus, means for permitting ordinarytalking and signaling currents to be transmitted through said circuit, and means for automatically transmitting alarms from said signaling apparatus to said receiving apparatus, and

4 telephonic communication between such apparatus. 4 1

17. A combined telephone and alarm system, comprising the combination of a plural.

ity of telephone instruments and alarmv instruments associated with each telephone instrument, a telephone exchange, a common ,circuit connecting each telephone and its corresponding-alarm instrument with the exchange, a common source of operating current for all of said alarm instruments, an, independent electrical connectionfrom each alarm instrument to the source of current, alarm receiving'apparat-us, and means connected with each common circuit for permitting signal andtalking currents to pass between'the exchange and the telephone instruments without affecting the alarm receiving apparatus, but causing signals from the alarm instruments to be transmitted to the alarm receiving apparatus.

18. Acombined telephone and alarm system, comprising a plurality of telephone instruments and alarm signaling instruments associated with each telephone instrument, a telephone exchange, a circuit having two leads connecting each telephone instrument with the exchange, a common source of operating current for all of said alarm instruments, an independent electric circuit connecting each alarm instrument, and a source of current and means for establishing electrical connection between said independ' cut circuit and both leads of the corresponding telephone circuit.

19. A combined telephone and alarm system comprising a telephone exchange, line wires leading therefrom, an alarm receiving instrument, a plurality of telephone instruments connected to said line wires, alarm signaling apparatus associated with each telephone lnstrument, an individual telephone instrument connected with each alarm signaling apparatus. a telephone instrument connected to the alarm receiving instrument, aml means for preventing the ordinary telephone and signaling currents between the subscribefis instrument and the exchange from being transmitted to the alarm receiv mg instrummit, but permit! ingalarm signals to be transmitted between the alarm signal,

said exchange, an auxiliary electrical instrument connected to each circuit adjacent its telephone instrument, a common complementary auxiliary electrical instrument, an independent electrical connection between the individual auxiliary instrument and the common auxiliary instrument, a source of operating current for said auxiliary instruments, and means for permitting ordinary talking and signaling currents to pass between the telephone instruments and the ex change without afl ecting the auxiliary instruments, but permitting signals to be transmitted between the "auxiliary instruments.

21. A combined telephone and auxiliary signal and recording system, comprising a telephone exchange, a plurality of subscribers telephone instruments, circuits connecting the telephone instruments with the exchange, an auxiliary electrical instrument connected with each telephone instrument circuit, centrally located complementary auxiliary electrical apparatus with means for'receiving and recording signals at said exchange, a source of operating current at said exchange for said auxiliary apparatus, and an independent electrical connection between each individual auxiliary instrument and the centrally located auxiliary apparatus.

22. A combined telephone and alarm system, comprising the combination of a telephone instrument, an alarm instrument, a telephone exchange, a common circuit connecting the telephone and alarm instruments with the exchange, a common source of operating current for said telephone and alarm instruments: an independent electrical connection from the alarm instrument. to the exchange, alarm receiving apparatus, and means associated with said common circuit irresponsive to the telephone signal and talking currents and causing signals from said alarm instruments to be transmitted to said alarm receiving apparatus.

' 23. A combined telephone and alarm s stem, comprising the combination of a p urality of telephone lines leading from subscribers stations to a central station, telephone sets at the subscribers stationsand telephonic apparatus at the central station coiiperatire therewith 'l'or conversational purposes, a plurality of auxiliary signaling instruments grounded at outlying points and adapted to transmit distinctive signaling currents over the telephone lines, alarm registeiing apparatus at the centralstation having mechanism responsive to distinctive sig naling currents from the auxiliary instruments but unresponsive to the telephone signaling and talking currents, alarm receiving apparatus outside the central station, and

phone circuit, an alarm receiving and re-,

cording device at said exchange, electromagnetic means irresponsive to the ordinary talkin and signaling curients for automatica ly transmitting distinctive signaling currents to said receiving'and recording device, private headquarters receiving apparatus, and means controlled by said exchange alarm receiving and recording device for automatically transmitting the distinctive signals to said private headquarters receiving apparatus.

25.. A combined telephone and alarm system, comprising the combination of a telephone exchange, a telephone instrument, a circuit connecting said instrument with said exchange, distinctive signaling apparatus connected to said circuit, alarm receiving and registering apparatus at the exchange, electro-m sponsive apparatus having a coil winding in each branch of said circuit irresponsive to the ordinary talking and signaling currents but responsive to distinctive signaling currents for transmitting said distinctive signaling currents to said alarm receiving and registering apparatus;

26. A combined telephone and alarm system, comprising a telephone exchange, a plurality of telephone instruments, circuits connecting said instruments with said exchange, distinctive signaling apparatus connecteclto a plurality of said clrcuits, alarm receiving and registering apparatus at said exchange, and electro-responsive mechanism including a coil winding in each branch of each circuit irresponsive to the ordinary talking and signaling currents but responsive to-distinctive signaling currents for transmitting the distinctive signals to said receiving and registering apparatus.

27. In a telephone exchange, the combination with a plurality of telephone lines leading from the subscribers stations to the central station, of telephone sets at the sub-stations and telephonic apparatus at the central station to cooperate with said lines for conversational purposes, alarm transmitting appa- V cooperate with said line for conversational purposes, distinctive signaling apparatus at an outlying point connected to said line, alarm receiving and registering apparatus at the central station, and electro-responsive mechanism including coil windings in each branch of the line responsive to the distinctive signaling currents but irresponsive to the telephone signaling and talking rrents.

29. The combination of a subscribers telephone and exchange, a circuit connecting said subscribers telephone and, exchange having an outgoing and an incoming lead, said circuit being grounded at the subscribers station and at the exchange and additional telephone receiving and transmitting apparatus'connected to the ground and inductively connected to both leads so as to transmit signals through the circuit made up of the ground connections in series and said two leads in parallel, a signaling transmitting apparatus electrically connected directly to one of said leads and a receiving relay connected to said leadat the exchan e vand in series with said signaling transmitting apparatus.

Signed by me in Philadelphia this 13th day of April, 1900.

JOHN MORRIS LATIMER.

Witnesses:

H. M. MEYEns, EDWARD EVERITT. 

